From Wikipedia: "The plates are installed in both the front and rear of the vehicle, with the rear plate permanently attached to the vehicle with a prefecture seal completely covering one of the attaching plate bolts."

...like with almost every other state mandated thing, you find ways around it...

That's funny, the top two examples that JunRaymond posted are the glowing plates (light boxes with translucent green letters that light up with the parking lights. They are illegal. So at least two people did find a way to remove and replace the seal in order to install the glowing plates.

...like with almost every other state mandated thing, you find ways around it...

That's funny, the top two examples that JunRaymond posted are the glowing plates (light boxes with translucent green letters that light up with the parking lights. They are illegal. So at least two people did find a way to remove and replace the seal in order to install the glowing plates.

negative, the glowing plates are not illegal.

your best is to put on an adjustable plate bracket, then buy another seal and have them put it on.

From tigerdude.com"Most vehicles > 660cc, have an official seal or neji protecting the upper left screw on the rear plate. It is a lock-tab-button which prevents plate swapping and theft. The registration isn't official unless this seal is in place. These seals have been in use since after the War, and certainly were in place when the number plate system saw standardization in 1951."

Based on what I've read from another guy's blog, you must break the anti-theft prefecture seal to remove the plates. But from what I understand, breaking the seal is illegal in some prefectures in Japan and only people from their transportation bureau can install/break the seals.

...breaking the seal is illegal in some prefectures in Japan and only people from their transportation bureau can install/break the seals.

yes it is. there are certain circumstances where you may break the seal without worry, say you wreck and need to remove/re-install the plate, no problem. but you need to go to vehicle registration, show them your paperwork, buy a new seal, and they will install it.